There exists a substantial body of evidence relating cancer in man to his exposure to N-nitroso compounds. Extensive laboratory tests on various species of animals strongly suggests N-nitroso compound exposure is casually related to cancer in animals.
This evidence includes the following:
Of the nearly one hundred N-nitroso compounds that have been tested, approximately eighty percent were active carcinogens for several animal species. PA1 Carcinogenic nitrosamines have specific organotrophic effects, irrespective of their roots of administration. PA1 Many N-nitroso compounds selectively produce cancer at various sites, such as the lung, stomach, liver and nasal cavity, in many animal species. PA1 Biochemical activation of nitrosamines such as dimethylnitrosamine (DMN) to activate proximate carcinogens has been shown to be similar in both humans and rodents. PA1 Repeated administration of low doses of N-nitroso compounds appears to be more effective in inducing cancers in rodents than administration of a single high dose. PA1 U.s. pat. Nos. 3,973,910, Method of Measuring the N-nitrosamine Content of a Sample by David H. Fine; 3,996,002 Method and Apparatus For Measuring the N-nitroso Compound Content of a Sample by David H. Fine; 3,996,009, Specific Compound Detection System by David H. Fine and David P. Lieb; 3,996,008, Specific Compound Detection System With Gas Chromatograph by David H. Fine, David P. Lieb and David P. Rounbehler; 3,996,003, Specific Compound Detection System With Liquid Chromatograph by David H. Fine and David Rounbehler; and 3,996,004, Detection System With Liquid Chromatograph by David H. Fine and David P. Rounbehler.
In addition, it is known that N-nitroso compounds can be easily synthesized in foods and in vivo from common and naturally occuring precursors. Therefore, in investigating a connection between cancer in man and his exposure to N-nitroso compounds, it is important to have information on both the content of preformed N-nitroso compounds in the environment and in food and the possible formation of these compounds in vivo. Unfortunately more knowledge is needed relating to how man's exposure to preformed N-nitroso compounds compared to the in vivo formation from various precursors. That these compounds chemically react and change form within the body has been a major problem to obtaining this information. N-nitroso compounds formed from precursors appear to be present in the body for a relatively brief period of time.
Accordingly, it is an objective of the present invention to provide a method for directly measuring in vivo N-nitroso compounds.
It is a further objective of the present invention to provide a method of measurement which is simple and inexpensive, thereby facilitating routine evaluation of thousands of compounds and foodstuffs.
It is a further objective of the present invention to provide a method of measurement that is sensitive to all N-nitroso compounds.
It is a further objective of the present invention to provide a method for measurement that will work with real, complex mixtures, such as foodstuffs where the precursors are present at true environmental levels.
It is still a further objective of the present invention to provide a method of measurement which is unambiguous, with little inherent possibility for false results.